This invention relates to a thin film magnetic head and, more particularly, to a thin film magnetic head which is superior in efficiency as a magnetic head, which can provide superior recording characteristics with low electric power, and which has hardly any chippings caused through sliding contact against the magnetic medium, and a method suitable for manufacturing the thin film magnetic head.
FIG. 1 shows one example, in cross-section, of a conventional prior art two-winding type thin film magnetic head, wherein good conductive metals are adhered, by a method such as evaporation, electrodeposition, sputtering deposition or the like, on a magnetic material substrate 101 to form metallic layers 103 and 104 which are etched by a photo-etching technique to form a required pattern. An upper portion magnetic material layer 102 of permalloy or the like is formed, by a method of evaporation, electrodeposition, sputtering deposition or the like and with the photo-etching technique, to partially cover the conductive body layers 103 and 104 through an insulating layer 105. In this thin film magnetic head, the magnetic material substrate 101 and the upper portion magnetic material 102 approach towards each other at a gap portion 106 disposed between the conductive body layers 104 and 103. Thus, the magnetic flux generated through current flowing to a coil 103 for signals is leaked at gap portion 106 between the magnetic material substrate 101 and the upper portion magnetic material 102 and does not reach the contact face 107 against the recording medium. In this conventional head, the efficiency is inferior during the signal recording operation and high power is required to flow to the coil for signals. If such high power is not provided, the recording operation is made difficult, thus resulting in the head being impractical to use.
Also, FIG. 2 is a cross-sectional view of the thin film magnetic head of FIG. 1, seen from the contact face 107 against the magnetic medium, wherein a protective film 111 is adhered on the upper portion magnetic body 102 and, furthermore, a protective substrate 113 is bonded by a bonding resin layer 112 to protect the thin film from sliding or abrasion with respect to the magnetic medium. However, in this construction where the conductive body layers appear on the contact face, chipping 114, flowing in the conductive body layer or the like, is caused on the surface of the conductive layer 104 during service, whereby the magnetic characteristics of the head become worse and the sectional area of the conductive body layer 104 where the current flows becomes smaller. In addition, the tolerance value of the recording current changes to cause heating and disconnection during service, thus resulting in the head being impractical to use.